Identification of Molecular Targets of Dietary Grape-Mediated Chemoprevention of Ultraviolet B Skin Carcinogenesis: A Comparative Quantitative Proteomics Analysis

Ultrasound treatment enhanced the functional properties of phycocyanin with phlorotannin from Ascophyllum nodosum

Introduction

Phycocyanin offers advantageous biological effects, including immune-regulatory, anticancer, antioxidant, and anti-inflammation capabilities. While PC, as a natural pigment molecule, is different from synthetic pigment, it can be easily degradable under high temperature and light conditions.

Methods

In this work, the impact of ultrasound treatment on the complex of PC and phlorotannin structural and functional characteristics was carefully investigated. The interaction between PC and phlorotannin after ultrasound treatment was studied by UV–Vis, fluorescence spectroscopy, circular dichroism (CD) spectroscopy, fourier transform infrared (FTIR) spectroscopy. Additionally, the antioxidant potential and in vitro digestibility of the complexes were assessed.

Results

The result was manifested as the UV–Vis spectrum reduction effect, fluorescence quenching effect and weak conformational change of the CD spectrum of PC. PC was identified as amorphous based on the X-ray diffraction (XRD) data and that phlorotannin was embedded into the PC matrix. The differential scanning calorimetry (DSC) results showed that ultrasound treatment and the addition of phlorotannin could improve the denaturation peak temperatures (Td) of PC to 78.7°C. In vitro digestion and free radical scavenging experiments showed that appropriate ultrasound treatment and the addition of phlorotannin were more resistant to simulated gastrointestinal conditions and could improve DPPH and ABTS+ free radical scavenging performance.

Discussion

Ultrasound treatment and the addition of phlorotannin changed the structural and functional properties of PC. These results demonstrated the feasibility of ultrasound-assisted phlorotannin from A. nodosum in improving the functional properties of PC and provided a possibility for the application of PC-polyphenol complexes as functional food ingredients or as bioactive materials.

Protective effects of dietary grape against atopic dermatitis-like skin lesions in NC/NgaTndCrlj mice

Atopic dermatitis (AD) is a chronic inflammatory skin disease with significant health/economic burdens. Existing therapies are not fully effective, necessitating development of new approaches for AD management. Here, we report that dietary grape powder (GP) mitigates AD-like symptoms in 2,4-dinitrofluorobenzene (DNFB)-induced AD in NC/NgaTndCrlj mice. Using prevention and intervention protocols, we tested the efficacy of 3% and 5% GP-fortified diet in a 13-weeks study. We found that GP feeding markedly inhibited development and progression of AD-like skin lesions, and caused reduction in i) epidermal thickness, mast cell infiltration, ulceration, excoriation and acanthosis in dorsal skin, ii) spleen weight, extramedullary hematopoiesis and lymph nodes sizes, and iii) ear weight and IgE levels. We also found significant modulations in 15 AD-associated serum cytokines/chemokines. Next, using quantitative global proteomics, we identified 714 proteins. Of these, 68 (normal control) and 21 (5% GP-prevention) were significantly modulated (≥2-fold) vs AD control (DNFB-treated) group, with many GP-modulated proteins reverting to normal levels. Ingenuity pathway analysis of GP-modulated proteins followed by validation using ProteinSimple identified changes in acute phase response signaling (FGA, FGB, FGG, HP, HPX, LRG1). Overall, GP supplementation inhibited DNFB-induced AD in NC/NgaTndCrlj mice in both prevention and intervention trials, and should be explored further.

Short-Term Grape Consumption Diminishes UV-Induced Skin Erythema

Over three million Americans are affected by skin cancer each year, largely as a result of exposure to sunlight. The purpose of this study was to determine the potential of grape consumption to modulate UV-induced skin erythema. With 29 human volunteers, we report that nine demonstrated greater resistance to UV irradiation of the skin after consuming the equivalent of three servings of grapes per day for two weeks. We further explored any potential relationship to the gut-skin axis. Alpha- and beta-diversity of the gut microbiome were not altered, but grape consumption modulated microbiota abundance, enzyme levels, and KEGG pathways. Striking differences in the microbiome and metabolome were discerned when comparing the nine individuals showing greater UV resistance with the 20 non-responders. Notably, three urinary metabolites, 2'-deoxyribonic acid, 3-hydroxyphenyl acetic and scyllo-inositol, were depressed in the UV-resistant group. A ROC curve revealed a 71.8% probability that measurement of urinary 2'-deoxyribonic acid identifies a UV skin non-responder. 2'-Deoxyribonic acid is cleaved from the DNA backbone by reactive oxygen species. Three of the nine subjects acquiring UV resistance following grape consumption showed a durable response, and these three demonstrated unique microbiomic and metabolomic profiles. Variable UV skin sensitivity was likely due to glutathione S-transferase polymorphisms. We conclude that a segment of the population is capable of demonstrating greater resistance to a dermal response elicited by UV irradiation as a result of grape consumption. It is uncertain if modulation of the gut-skin axis leads to enhanced UV resistance, but there is correlation. More broadly, it is reasonable to expect that these mechanisms relate to other health outcomes anticipated to result from grape consumption.

Construction of the coexpression network involved in the pathogenesis of thyroid eye disease via bioinformatics analysis

Background

Thyroid eye disease (TED) is the most common orbital pathology that occurs in up to 50% of patients with Graves’ disease. Herein, we aimed at discovering the possible hub genes and pathways involved in TED based on bioinformatical approaches.

Results

The GSE105149 and GSE58331 datasets were downloaded from the Gene Expression Omnibus (GEO) database and merged for identifying TED-associated modules by weighted gene coexpression network analysis (WGCNA) and local maximal quasi-clique merger (lmQCM) analysis. EdgeR was run to screen differentially expressed genes (DEGs). Transcription factor (TF), microRNA (miR) and drug prediction analyses were performed using ToppGene suite. Function enrichment analysis was used to investigate the biological function of genes. Protein–protein interaction (PPI) analysis was performed based on the intersection between the list of genes obtained by WGCNA, lmQCM and DEGs, and hub genes were identified using the MCODE plugin. Based on the overlap of 497 genes retrieved from the different approaches, a robust TED coexpression network was constructed and 11 genes (ATP6V1A, PTGES3, PSMD12, PSMA4, METAP2, DNAJA1, PSMA1, UBQLN1, CCT2, VBP1 and NAA50) were identified as hub genes. Key TFs regulating genes in the TED-associated coexpression network, including NFRKB, ZNF711, ZNF407 and MORC2, and miRs including hsa-miR-144, hsa-miR-3662, hsa-miR-12136 and hsa-miR-3646, were identified. Genes in the coexpression network were enriched in the biological processes including proteasomal protein catabolic process and proteasome-mediated ubiquitin-dependent protein catabolic process and the pathways of endocytosis and ubiquitin-mediated proteolysis. Drugs perturbing genes in the coexpression network were also predicted and included enzyme inhibitors, chlorodiphenyl and finasteride.

Conclusions

For the first time, TED-associated coexpression network was constructed and key genes and their functions, as well as TFs, miRs and drugs, were predicted. The results of the present work may be relevant in the treatment and diagnosis of TED and may boost molecular studies regarding TED.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40246-022-00412-0.

Photoprotective Mechanism of Fucoxanthin in Ultraviolet B Irradiation-Induced Retinal Müller Cells Based on Lipidomics Analysis

Long-term exposure to sunlight and/or blue light causes vision damage to people of all ages. Dietary pigments and polyphenols have been shown to have photoprotective potential for eyes; however, many unknowns regarding the protective mechanism remain. In this study, we used ultraviolet B (UVB) irradiation-induced retinal Müller cells (RMCs) to screen for dietary polyphenols and pigment compounds with effective photoprotective activity. Fucoxanthin (FX) was shown to have the best therapeutic effect, and the mechanism was evaluated via lipidomics analysis. Both intra- and extracellular ROS, mitochondrial depolarization, and DNA damage induced by UVB irradiation were inhibited by FX. Meanwhile, FX modulated the MAPK signaling pathway, which is correlated with apoptosis and inflammation. Our lipidomics data revealed that FX regulated lipid metabolism disorder and protected the membrane structure. These results confirm the effective photoprotective effects of FX, which may lead to new insights into FX-functionalized photoprotective foods.

Increased lipid peroxidation by graphene quantum dots induces ferroptosis in macrophages

Graphene quantum dots (GQDs) are an excellent tool for theranostics, and are widely used in nanomedical applications. The biosafety of GQDs has received abundant attention, but their latent toxicological mechanisms remain inadequately understood. To investigate the cellular and molecular mechanisms underlying graphene-mediated changes, quantitative proteomics and untargeted lipidomics were integrated. We discovered that glutathione peroxidase 4 as a key regulator of ferroptosis, was down-regulated at the protein level by GQDs. Lipidomics profiling with features of ferroptosis was identified in GQDs-treated RAW264.7 macrophages. Furthermore, GQDs exposure was associated with reduced levels of GSH and increased lipid peroxidation. Overexpression of GPX4 in RAW264.7 cells and pre-treatment of a ferroptosis inhibitor Ferrostatin-1 (Fer-1) not only suppressed cell death, but also alleviated lipid peroxidation. Taken together, our results indicated that GQDs exposure induced ferroptosis in RAW264.7 macrophages, and provided essential data for biosafety evaluations of GQDs.

Novel insights into plasma biomarker candidates in patients with chronic mountain sickness based on proteomics

Chronic mountain sickness (CMS) is a progressive incapacitating syndrome induced by lifelong exposure to hypoxia. In the present study, proteomic analysis was used to identify the differentially expressed proteins (DEPs) and then evaluate the potential plasma biomarkers between CMS and non-CMS groups. A total of 145 DEPs were detected in CMS Han Chinese people who live in the plateau (CMS-HPu), among which 89 were significantly up-regulated and 56 were significantly down-regulated. GO enrichment analysis showed that various biological processes were enriched, including the hydrogen peroxide metabolic/catabolic process, reactive oxygen species (ROS) metabolic, and acute inflammatory response. Protein–protein interaction analysis showed that antioxidant activity, the hydrogen peroxide catabolic process and peroxidase activity were primarily mapped in interaction proteins. Nine modules showed significantly clustering based on WGCNA analysis, with two being the most significant, and GO analysis showed that proteins of both modules were primarily enriched in oxidative stress-related biological processes. Four DEPs increased in CMS patients were evaluated as the candidate biomarkers, and three showed significant AUC: hemoglobin β chain (HB-β), thioredoxin-1 (TRX1), and phosphoglycerate kinase 1 (PGK1). The present study provides insights into the pathogenesis of CMS and further evaluates the potentially biomarkers for its prevention and treatment of it.

Comprehensive Profiling of Proteome and Ubiquitome Changes in Human Lens Epithelial Cell Line after Ultraviolet-B Irradiation

Ultraviolet-B (UVB) is a recognized risk factor for age-related cataract (ARC) and can cause various changes, including ubiquitination, in lens epithelial cells (LECs). However, the relationship between ubiquitination and ARC is unclear. Herein, we used UVB-irradiated human lens epithelial cell line (SRA01/04) representing the cell model of ARC to investigate the profile changes in the proteome and ubiquitome. A total of 552 differentially expressed proteins (DEPs) and 871 differentially ubiquitinated proteins (DUPs) were identified, and 9 ubiquitination motifs were found. Bioinformatics analysis revealed diverse pathways and biological processes of differential proteins and several DNA damage repair proteins that were potentially mediated via ubiquitin-proteasome pathway. We validated the decreased protein expression of DNA-directed RNA polymerase II subunit RPB2 (POLR2B) in both human cataract capsule tissues and UVB-treated SRA01/04 cells and found that treatment with proteasome inhibitor (MG-132) could reverse the protein level of POLR2B in UVB-irradiated SRA01/04 cells. Our data provide novel information regarding protein expressions and ubiquitination modifications in UVB-induced oxidative damage model. This study might offer a cell-level reference to further investigate the pathogenesis of ARC.

Protective Effects of Dietary Grape on UVB-Mediated Cutaneous Damages and Skin Tumorigenesis in SKH-1 Mice

Non-melanoma skin cancers (NMSCs) are the most diagnosed cancers in the US and occur more frequently in males. We previously demonstrated chemoprotective effects of dietary grape powder (GP) against UVB-mediated skin tumorigenesis in female SKH-1 mice. To expand on this, here, we determined the effects of GP in a short-term UVB exposure protocol (0 or 5% GP, followed by UVB every other day for 2 weeks) in male and female SKH-1 mice, as well as explored any sex-related differences in UVB carcinogenesis via male SKH-1 mice (0, 3, or 5% GP; UVB twice weekly for 28 weeks). In the short-term study, we found that GP protects against early-stage epithelial hyperplasia and mast cell infiltration in both sexes. In the long term, GP markedly reduced tumor counts and malignant conversion, along with significant decreases in mast cell infiltration, serum IgE and Eotaxin. We also found inhibition of P38 phosphorylation and reduced PCNA, Ki67 and BCL2 levels, suggesting that the anti-inflammatory effects of GP inhibits P38, acting as an upstream regulator to inhibit proliferation and reduce tumor cell survival. Together, GP appears to protect against UVB-mediated skin damage and carcinogenesis in SKH-1 mice and should be explored further as a supplement for NMSC prevention.